HW Cylinder stat failure / IH stat failure?

[londonboy123]

Just a question (probably sounds dumb) but to put my mind at ease after reading through some posts on here lately.

If a cylinder stat or an immerson heater thermostat fail (on an opne vented system) - the water will probably boil (unless the thermostat on the immersion heater was a newer model and had a cut non-self ressetting cut out device and the heater simply wouldn't heat). Would this mean water would be coming out of the primary vent pipe and into the CW tank?

Otherwise how else would you know either had failed?

 

[Gasguru]

Steam/water from vent, normally the expectation of the cylinder exploding (from the noise) will force occupants to turn off the heater. And worst case scenario...the cold cistern cooks and fails.

 

[algeep]

if the emmersion thermastat was faulty and did not disengage then the tank would eventually boil but if water heated by boiler the boiler stat would surely disengage the hotwater even if the tank stat had failed

 

[londonboy123]

the reason i ask is as i fitted a new thermostat on my cylinder about 5 months ago - and tested it (it turned on and off properley). but if the sensor part blew and didn't shut off the supply at 60 degrees (which i have set it at) - how would i know? The water from my hot tap is hot (i cant keep ym hand under it for long at all without it buring me - but i thought this was usual at 55 degree tap temp)!!!??

I am just curious to know how I would definitely know if it was faulty in the future really?

As you said the boiler stat (set at about 80 degree c) would stop the water boiling, but how would I know the cylinder stat sensor was faulty (going above 60 degree c)??

 

[algeep]

set the boiler stat to max give the water time to fully heat up in the cylinder then run the nearest hot tap use a themometer to take the temp if the tank stat is set to 60 and the waters 80+ you know the tank stat is not shutting down the demand on hot water